I had the driver's side a/c actuator replaced. It had been occasionally starting to blow hot air on the driver's side. To reset it I had to turn off the ignition and start it up again. It would never test "bad" at the dealers, but it just "had to" be the problem so I told the dealer to just replace it regardless of how it tested. It tested good, but after it was removed and tested on the bench it was in fact not working correctly. This type of problem is a real pain, but all it working great now.
2006 GMC 2500HD CCSB 4x4 Duramax/Allison, Titan 52 gallon fuel tank, Prodigy Controller, B&W Companion Hitch
2010 Jayco Designer 35RLTS, Cummins/Onan RV QG 5500 EVAP, Progressive Industries EMS-PT50C, TST Systems 507 TPMS, RV Flex Armor Roof